1. Role of impurities in current tokamak experiments
2. Some observations on maximum densities in tokamak experiments
3. Radiation limits to tokamak operation
4. P. H. Rebut and B. J. Green, inPlasma Physics and Controlled Nuclear Fusion Research, Proceedings of the 6th International Conference, Berchtesgaden, 1976 (IAEA, Vienna, 1977), Vol. II, p. 3.
5. Density limit in tokamaks